Antenna structure



June 14, 1927.

' A. A, OSWALD ET A1.

n ANTENNA STRUCTURE Filed Jan. 4. '1924 Patented June l14, 1927.

UNi'lEl QFFICE..

ARTHUR A. OSVJALD AND EDVARD L. NELSUN, @E EAST GHANGE, NEW JERSEY, AS-

SIGNRS TU VESTERN ELECTRBG C'Gh-"All, NCORPGRATED, CHF NEW YORK. N. Y.,

A COREORATION OF NEE? YORK.

ANTENNA STRUCTURE.

' Application led January 4t, 1924i..

This invent-ion relates to an ani enna.y structure and more particularly to a sectionalized cage antenna and associated down lead.

Cage antennae heretofore proposed have been provided with cone or one point connections to the supporting` masts or towers and the individual conductors ot the antenna have each been connected to the separate wires ot a cable which constitutes the l0 down lead. In certain cases, the lead wires werecarried by spreaders in the torni ot' a cage. One disadvantage oi this arrangement resides in the fact that in high winds or on ship board the single point connection permits the antenna to turn or twist about its longitudinal axis. with the result that the electrical characteristics ot the antenna vary. Again when the antenna rolls or twists an unequal tension is produced in the different wires or the cage and down lead, which at times has caused one or more oi the antenna or down lead wires to break, whereby the electrical characteristics of the antenna are changed.

The present invention provides an antenna system comprising a plurality of cage sections and a cage down lead so connected mechanically that the antenna as a whole is'prevented from turning or twisting` and any strain applied to the system produces a uniform tension in each conductor of the antenna sections and down lead. The systeni also includes meansl for effecting a symmetrical electrical connection between the individual conductors or strands oi the antenna sections and the separate conductors of the down lead.

In accordance with this invention the individual conductors'or strands ot the ant-enna sections and the down lead are tastened to a terminal ring,` having iixedly secured to it a tie piece or yoke provided with an end portion having' extended parallel surfaces adapted to be securely held in en- '45 @agement with plane surfaces of a 'coupling glement for mechanically connecting the yoke and coupling element together. The down lead is connected to the coupling element. at a point oilset relatively to the horizontal plane including the connecting points `tor the antenna sections and therefore prevents any tendency of these sections to roll or rotate about the longitudinal et the structure.

Serial No. 684,254.

The ends et the individual strands ot each ol the antenna. `sections are electrically connected to one end ot a conductor or cable the other end ot which is electrically connected to the ends ot the separate strands constituting the down lead and the connectine' cables are ot such length that under the most adverse conditions no tension is applied to them.

@ne object, oi? this invention is to provide a cage antenna the electrical characteristics ol2 which are substantially constant.

Another object is the provision of a substantially rigid cage antenna.

'll another object is to provide 'for applying a sulgistantially uniform tension to the individual strands ot a cage antenna and associated down lead.

fr feature of the invention is an antenna system comprising' a cage antenna associated with its down lead by separate mechanical and electrical connections.

A still further object is the provision of means., adapted to connect the separate strands o1c a cage antenna7 and the individual strands ot a cage down lead together electrically, which is symmetrically related to the two groups or strands.

For a complete understanding of the invention reference should be made to the following' description read in conjunction with the attached drawing` in which Fig. 1 shows a cage antenna embodying the invention;

Figs. 2 and 3 illustrate details of the antenna structure; and

Fig'. a shows an antenna system comprisine' a number of cage sections,

in Fig. l there is shown an antenna con- :Sistina` of cage sections l and 2 carried on supporting' masts or towers 8 by cables 4 secured to the outer extremities of the sections l and 2. The cables i pass over pulleys 5 and are secured to windlasscs G upon which they may be wound to raise the antenna system and control the strain applied to it. rlhe inner extremities ot the antenna sections are mechanically connected together and to the upper end ot a down lead by a coupling` element- S. The down lead T, as is well known, serves to electrically connect the antenna to the apparatus of a radio system. rl`he outer ends ot the sections l and 2 are connected to the cables 4 by insulators loafer end of the down lead secured to an anchor bolt 9 through an insulator 11.

As shown in Fig'. 2 the antenna Sections and down lead consist ol six wires or conductors 1L. 'lhese conductors are held in proper spaced relation by metallic ring or hoop spreaders 13 to the outer periphery of which they are secured by tie Wires 14.

Each tie wire is made a component part of the spreader by being' Wound upon and secured thereto, as by soldering or Welding,

in such a manner as to leave a space transversely ol the ring 13 to receive the antenna or down lead conductor 12. The conductor 12 is laid upon the outer peripheral Surface of the ring 1.3 in the space bounded by the tie Wire windings and the ends of the tie wires are .Wrapped about the antenna conductor 12 at opposite sides of the ring 13. By aliiplying the proper tension to the tie wires, the conductors 12 may be bent or crimped at opposite edges of the rings 13, whereby these conductors are securely held in fixed position on the spreaders. If found desirallle the tie wires 14 may be soldered or welded to the conductors 12 and the latter n'iay be similarly secured to the rings 13.

By this arrangei'nent a single tie. Wire is used to prevent each of the conductors from slipping circumferentially of the spreader and also to prevent the spreader from slipping longitudinally ofthe conductors. One advantage of this form of fastening resides in the fact that the tie Wires may be fastened to the spreaders in the shop and the antenna conductors secured thereto during field eonstruction thereby simplifying the` latter operation. I

Fig. 3 illustrates an end fitting for the antenna sections and down lead. The scale of this figure has been exaggerated in order to show details of the construction.

The end fitting' comprises a metallic ring 15 provided with a tie piece or yoke 1G which is secured in fixed relation to the ring in any well lknown manner, such as, 'for example, by riveting or welding, or by making the fitting from one ieee of metal. The ring 15 is provided with a plurality ofvpertorations -or holes 17 into each of which is inserted an ordinary cable or rope thimble 1S. Each antenna and down lead strand or conductor 12 after having its end threaded through a hole 17 in engagement with the thimble. 18 is bent back and secured to the main portion of the strand as at 19, by awire sizing or Wrapping which is then preferably soldered. i Adjacent the coupling 8, the end of each of the antenna and down lead conductors projects beyond the joint 19. The projecting ends of the conductors are grouped centrally of thering 15 and areconnected to a conductor or cable 20 which serves to conductively connect the separate Wires or strands of the antenna sections to those of the down lead. ln this manner the ljoint between the col'lductors 12 and cable 2() is syinnietri'ally positioned relatively to the ring 15.

The mechanical coupling element 8 is herein shown as a plate substantially lrangular in forni. lhe yoke lo olf the end fitting is shown as a circular rod having its ends 21 flattened, and bent back to engage both peripherial surfaces and one end sur- 'lfare of the ring 15. The mid portion of. the rod is shaped to provide an eye 22 through which passes :l bolt or other similar device for securing the yoke to the coupling plate S. The eye section 22 of the yoke constitutes an extendedsur'lace which is held in engagement with a similar plane surface of the plate 8. Any strain aljiplied through the cables 4l: will be transmitted solely by the coupling element S to the down lead 7. rThe aerial sections are connected to the element 8 at points lying in a horizontal plane and the down lead is connected to the plate at a point lying outside this plane. Due to the strain applied to the system by the cables 4, the down lead Will maint-ain the plate 8 in a vertical plane and because the yoke 16 engages the plate 8 over an extended area, the sectionsof the aerial will be prevented from turning or twisting relatively thereto and hence to one another.

The yoke 1 6 may have any cross section and the coupling element 8 may have any desired form so long as their engaging surfaces are such to preventl rotation of the end fitting relatively to the coupling element, and the down lead is connected to the coupling element at a point adapted to maintain this element under all conditions in the same position relatively to the antenna sections.

In an antenna structure, it will be apparent that there Will be some sag at the centre and hence the structure will not lie in a horizontal plane. In a similar manner, if the down lead is'ereeted to lie in any but a vertical position, there will be some sagr depending upon its departure from the vertical position. Because of this fact and in order to produce a substantially uniform tension in each of the conductors constituting an antenna section or down lead, due to vstrain applied to the cables 4, the, lengths of the conductors of these elements should be slightly different or the conductors` should be made equal and one end fitting for each section or down lead should be rotated a definite amount, whereby the conductors are spirally positioned relatively to the central axis and a substantially uniform tension is produced in each conductor.

Because of the fiexible connection between the antenna and down lead, any additional strain due to Wind pressure, etc., will be distributed equally among the elements ot the system and hence the tension applied to the down lead which tends to prevent the antenna from rotating or rolling about its longitudinalaxis, will increase in proportion to Ahe added strain.

An antenna structure consisting ot tvvo ,ctions and a. single uown lead has been dcscribed, however, any number of sections may be used.

ln Fig. a', there is shown, on a reifiuced scale, an antenna system comprising tour cage sections. rlhe adjacent sections lll-32, 32h33, 323-34- are mechanically connected together by coupling elements 5S. A cable 2() is used to electrically connect section 3l to section 32 and section 33 to section it ',lhe coupling element for the midsectionsI 32 and 33 are connected by a down lead T to an eyebolt 9 and the coupling elements :for the adjacent sections 31-32 and Bdfl are connected to similar eye bolts by guy vWires C155 and 36, respectively. ln this manner, the di'llerent coupling elements are anchored so that relative turning movement ci' the dil'- lierent sections and the antenna as a whole is prevented. bviously, anchoring means similar to 7 could be used in place ot the guy Wires 35 and 36.

A six-Wire cage section has been described. However, the features of the invention are applicable to cage sections having any number of Wires.

From the preceding description, it Will be seen that this .invention provides a cage antenna which is exceptionally rigid in construction and has substantially constant electrical characteristics.

It .is to be understood that, While certain details have been described in order to completely and clearly disclose the invention, this invention is not limited to the specific teatures set torth, but only by the scope ot the att-ached claims.

hat is claimed is:

l. An antenna comprising a plurality ot cage sections, a down lead, means Jfor electrically connecting said sections to said down lead, and means connected to said sections to prevent the antenna from rolling.

2. An antenna comprising a plurality of cage sections, a down lead, means for electrically connecting said sections to said down lead, and means mechanically connecting the down lead to said sections to prevent rotary movement of said sections.

8. An antenna comprising a cage section, a terminal spreader tor said section having a tie piece rigidly secured thereto, a down lead electrically connected to said section, and means mechanically connected to said tie piece to prevent said section from turning or rolling.

t, An ant-enna comprising a plurality of cage sections, a terminal spreader for each section having a tie piece rigidly secured thereto, a dou'n lead electrically connected to said sections, and means tor meclmnically connertinn said tic pieces so that rolling or turning or said sections is prevented.

5. i3 antenna con'iprising a plurality of cage sections. terinii'ial spreaders tor each section, each spreader' having a tie piece rigidly secured thereto, means tor rigidly connecting the tie pieces ot adjacent spreaders, and means lior maintaining said connecting means in lined position relatively to said tie pieces.

(i. An antenna comprising a plurality ol' cage sections, a down lead electrically connected to said scctionz-i, terminal spreaders Yfor each section and said down lead, each spreader having a tie piece rigidly secured thereto, means tor rigidly connecting the tie pieces ol the ladjacent section and down lead sprcaders, whereby relative rotary motion ot said sections prevented.

7. A cage antenna comprising` a plurality ot conductors, terminal spreaders therefor, eafh consisting of a spacing element and a tie piece rigidly secured thereto, said spacing clement having a plurality of perforations through each of which the end of one or' said conductors is threaded, bent back and secured to the main portion of the conductor.

8. An antenna system comprising a. plurality of cage sections having a plurality of conductors, and a down lead, means for symmetrically electrically connecting the conductors oit' the cage sections to said down lead, means for mechanically connecting said sections and down lead so that any strain applied to the antenna will produce a unilorm tension in each of said conductors While preventing the antenna from turning or twisting,

9. An antenna system comprising a plurality or' cage sections and a cage down lead each having a plurality ot conductors, means tor symmetrically connecting the conductors ot said sections and the conductors of said down lead, means for mechanically connecting adjacent ends of said sections and down lead so that any strain applied to the system Will produce a uniform tension in each ot the conductors of the sections and down lead While` preventing rotary motion of the antenna.

10. An antenna comprising a plurality ot cage sections and a down lead each consisting ot a plurality of Wires separately connected to terminal spreaders, said spreaders comprising a spacing element having atie piece rigidly secured thereto, means for connecting the tie pieces at the adjacent ends of said sections and down lead to prevent twisting and turning of the antenna as a Whole While permitting strains applied thereto to produce a uniform tension in each of the antenna and down lead conductors, and means symmetrically positioned relatively to said spacing elements :tor electrically connectingr the conductors of said sections and to the conductors of said down lead.

11. A cage antenna comprising a pluf rality oi conductors and a plurality of ring spreaders, means for securing each of said conductors to one peripheral surface of each of said spreaders in spaced relation, coniprising;r a tie wire having its. intermediate portion engaging the opposite peripheral surface of the spreader and Wound thereupon to constitute spaced Wrappings between Wliich an antenna conductor is laid,

the ends of said tie wire being wound upon said conductor at opposite sides of the spreader. l

12. An antenna comprisin a plurality of cage sections, and an anti-rol ing means connecting said sections.

13. An antenna comprising a plurality of cage sections, a down lead therefor, and means for coupling said cage sections and down lead for producing a uniform tension in each conductor of each cage section.

In witness whereof, We hereunto subscribe our naines this $3 day of January A. D., 1924.

ARTHUR A. OSVVALD. EDWARD L. NELSON. 

